The present invention relates to a laser therapy system and method for cutting and vaporizing a tissue body. More specifically, the invention is directed to an improved system and method for cutting and vaporizing a tissue body utilizing a fiber optic which is inserted into the lumen of a catheter and operable between an extended position wherein a distal end portion of the fiber optic is positioned to cut and vaporize a tissue body and a retracted position wherein the fiber optic is received within the lumen of the catheter. The catheter incorporates at a distal end portion a means for removing attached tissue fragments and the like from the distal end portion of the fiber optic.
Laser therapy techniques have been utilized in a variety of surgical procedures in a variety of specialties for a number of years. For example, laser techniques find applications in urology, gynecology, general surgery, ENT and other surgical specialties. Generally in laser techniques, a fiber optic is inserted into a working channel of a cystoscope and directed to a treatment sight where a tissue body is located. At the treatment sight the tissue body is then photoirradiated with a sufficient quantity of energy to cut, vaporize, and coagulate the tissue body.
Laser therapy has been a preferable alternative to conventional surgical procedures for a number of reasons. First, a surgical procedure can be performed with local disease control with functional and cosmetic results superior to standard techniques. Second, a surgical procedure can be performed with a drastic reduction in patient trauma and morbidity. Third, the overall surgical procedure time is reduced with the use of laser therapy as opposed to conventional techniques.
More recently, laser technology has been useful in the management of bladder-outlet obstruction due to prostatic hyperplasia (i.e. prostate swelling). Prostatic hyperplasia has been traditionally treated with a technique known as transurethral rejection of the prostate (TURP). This procedure utilizes an electrocautery loop which cuts, for example, a urethral obstruction into pieces thereby freeing the bladder passage. Although this technique has proven successful and represents a major advance over open surgical prostatic enucleation, there still remains a significant post-operative morbidity and patient trauma associated with this procedure. Laser therapy is used to supplement the TURP treatment and in some cases completely replace the need for TURP.
One of the problems associated with laser therapy has been the difficulty of directing the laser energy from the distal end of the fiber optic to the tissue body. This is because the surgeon would have difficulties viewing the procedure when fragments and debris engulfed the distal portion of the fiber and blocked viewing through a conventional cystoscope. In order to alleviate this problem LASERSCOPE.RTM. SURGICAL SYSTEMS developed an improved fiber system incorporating an Angled Delivery Device (ADD).TM. which directed the laser energy from the fiber axis as opposed to the distal end of the fiber. This allowed for improved viewing by the surgeon because the viewing light would not be detracted through the fragments and debris when viewed through a cystoscope. The ADD.TM. consist of a metal cannula having a fiber optic inserted therein which is manufactured to deflect at the distal end portion laser energy approximately 70 degrees off the central axis of the fiber. The metal cannula has an opening at a distal end portion which is filled with a glass thereby creating a window through which laser energy from the fiber is projected. With the development of the ADD.TM., however, it became critical to remove the fragments and debris which became stuck on the side of the distal end of the ADD.TM. during the vaporization procedure. If the fragments and debris are not removed, the laser energy is not permitted to effectively cut and vaporize remaining tissue body. Moreover, if the fragments are allowed to remain on the outer surface of the ADD.TM., an insulation effect is generated and a large heat build up will occur which melts the glass window and degrades the fiber. More recently, LASERSCOPE.TM. SURGICAL SYSTEMS has developed an ADD.TM. STAT which is utilized in a number of surgical procedures including the management of prostate swelling. This system comprises a fiber optic with an outer plastic sheath and a glass end cap secured on the distal end portion of the sheath. The ADD.TM. STAT does not utilize a metal cannula as with the ADD.TM.. When using the ADD.TM. STAT fragments and debris will become attached to the glass cap which must be removed for the same reasons described above. In this, the surgeon is required to remove the fiber system from the cystoscope and wipe the window or cap free of tissue fragments and debris which drastically extends procedure time and patient trauma.
As noted above, fragment and debris removal is more critical when the ADD.TM. or ADD.TM. STAT is used as opposed to distal end emitting fibers. However, such fragment and debris build up on the fiber system is disadvantageous in all laser therapy procedures whether the laser energy is side or end directed.
The difficulties and limitations suggested in the preceding are not intended to be exhaustive, but rather are among many which demonstrate that although significant attention has been devoted to laser therapy systems and techniques, the laser therapy systems and techniques appearing in the past will admit to worthwhile improvement.